Currently available processes for the commercial production of many proteins are complex, require numerous purification steps, and lack efficiency. Large scale purification of, for example, plasma-derived proteins is commonly performed by alcohol fractionation based on the methods of Cohn established over 50 years ago (Cohn et. al., J. Am. Chem. Soc, 68, 459 (1946)). Production yields for such proteins are low while manufacturing costs are high. However, affinity chromatography has been proven as an effective and efficient alternative for purifying a protein from a complex (heterogeneous) protein mixture. Affinity chromatography using peptide ligands has advantages over immunoaffinity chromatography which employs antibodies (Baumbach & Hammond, BioPharm, 5, 24–35 (1992)). Peptide ligands consist of only a few amino acids, which, unlike large murine antibodies, are not likely to cause an immune response if contamination of the purification product occurs. Peptide ligands also are more stable compared to antibodies, and can be manufactured aseptically in large quantities under Good Manufacturing Practice conditions. The interactions between peptide ligands and target proteins can be easily modified to allow mild elution conditions for separation and to provide greater control of interactions by the practitioner.
Due to the lack of existing ligands for purification of some proteins, affinity chromatography has yet to be applied for commercial scale purification of many plasma-derived proteins. Despite advances in other protein purification techniques, many current separation methods are inefficient in avoiding contamination with undesired proteins. Accordingly, there remains a need in the art for alternative materials for the efficient separation of plasma proteins from complex mixtures. The invention provides such materials and methods of use. These and other advantages of the invention, as well as additional inventive features, will be apparent from the description of the invention provided herein.